Is Idling Really an Issue for Gas Engines?

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670hoth

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There’s a small workaround. You can adjust your idle rpm up to increase oil pressure. Most guys are adjust it from the factory 600 which is supposed to keep your fuel usage at idle to a minimum up to between 650-750. Mine is adjusted to 650 and next tuning revision may push it to 700. My hot idle oil pressure is 38-40psi at 650 rpm. At 600 rpm my hot oil pressure would drop to 32-35 psi.
I can't help but Wonder if this would put more stress on the torque converter / transmission. For that matter even the engine. If you've got it and drive with your foot on the brake isn't it going to want to move forward more?
 

crazykid1994

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I can't help but Wonder if this would put more stress on the torque converter / transmission. For that matter even the engine. If you've got it and drive with your foot on the brake isn't it going to want to move forward more?
It would be minute if anything. The transmission being locked in first gear means no spinning in the trans so no extra wear on the clutches. Yes the engine is pushing the converter a bit faster but the converter is not locked so it’s just spinning mostly free. The oil pump in the trans is spinning ever so slightly more to what extent is that. The engine shouldn’t care much since it’s pumping more oil which helps with better lubrication to the top end. On the engine wanting to push the truck more I’m not sure. Mine feels the same. What rpm does the truck actually start moving though when you push the accelerator? The TC does have so much slip before it actually pushes. It’s not loading up the converter until over 1000rpm as a rough guess since I’m not in my truck currently.
 

JerryETX

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For me idling is an issue in part because of low oil pressure but more so due to carbon build up. Idling at low speeds doesn't burn off carbon fast enough and can leave carbon residue in the engine. This can happen in diesels too but obviously not as much since a diesel burns hotter than a gas engine. I've seen videos where the inside of the oil pan was caked with black carbon build up. If the oil pan is caked the engine likely is too. Also while you're not putting miles on an engine idling you're still using most other parts under the hood which can wear those parts out faster.

That said I've had work trucks that have never turned off and were left idling many days out of the week and went around 180k miles with no engine issues but again I've seen engines that were killed by excessive idling.

Changing the oil more frequently can help. I also believe the carbon build up isn't as bad in cold temperatures as it is in hot temps. Just my thoughts.
 

crazykid1994

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For me idling is an issue in part because of low oil pressure but more so due to carbon build up. Idling at low speeds doesn't burn off carbon fast enough and can leave carbon residue in the engine. This can happen in diesels too but obviously not as much since a diesel burns hotter than a gas engine. I've seen videos where the inside of the oil pan was caked with black carbon build up. If the oil pan is caked the engine likely is too. Also while you're not putting miles on an engine idling you're still using most other parts under the hood which can wear those parts out faster.

That said I've had work trucks that have never turned off and were left idling many days out of the week and went around 180k miles with no engine issues but again I've seen engines that were killed by excessive idling.

Changing the oil more frequently can help. I also believe the carbon build up isn't as bad in cold temperatures as it is in hot temps. Just my thoughts.
Even though I’m not an engineer I would think carbon buildup should be less in Hotter climates as the engine will run hotter. And diesel only runs hotter under load. Diesels that excessively idle with the DPF and other emissions tend to have worse carbon buildups that will choke the engine because they can’t get hot enough to burn the carbon off. Diesel engines that are worked tend to live a cleaner life
 

JerryETX

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Even though I’m not an engineer I would think carbon buildup should be less in Hotter climates as the engine will run hotter. And diesel only runs hotter under load. Diesels that excessively idle with the DPF and other emissions tend to have worse carbon buildups that will choke the engine because they can’t get hot enough to burn the carbon off. Diesel engines that are worked tend to live a cleaner life
Fair point could be dead on I was speaking solely from where I've seen these engines with excessive carbon build up being in Texas (in a hotter climate) and guys up north leave their vehicles running in the winter for days, sometimes weeks when it's really cold.
 

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I always thought heat was a big deal when idling. I had a Grand Marquis (Crown Vic) with and OBD reader and Torque app. If I was idling for the AC, Intake temp could easilly get over 150 with ambient of 90. Water temp would stay stable. I wouldn't think any engine internals would notice, but external stuff (manifolds, valve cover, rad and hoses) might age quicker.
 

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Hotter climates = faster oil oxidation, varnishing

Colder climates = sludge and emulsion formation

They're sort of book ends. For engine lubrication where you have byproducts of combustion blowby. For gear boxes, there is no sludging (unburned hydrocarbons), but high temp oxidation and emulsion from breather air moisture. That's why you can change gearboxes infrequently, as long as you don't overheat them.
 

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I'm not looking to get into an argument with @Rlaf75, or anyone else, and I don't disagree with him about idling in general. I just haven't seen any real proof that idling is what causes the cam/lifter issue on Hemi engines. There are also theories that MDS is the cause, or the design of how the cam gets insufficient lubrication, especially at lower rpm's. But like the idling theory, I haven't seen any real proof that any of those have been definitively shown to be the cause.

werd. one of our company trucks with 6.4 has over 5000hr idle. another one got wrecked and totaled but had several thousand idle also
 

Dodge Lover

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Police cars and taxis. Would I buy a used one? No. But then, I have seen police cars with 200k and no real issues. Part of my old agency had assigned cars, and those would be nicer than the pool issued cars, driven by multiple drivers. YMMV....
Heheheh.
The Game Warden branch of the Oregon State Police visits some of our Hunter Education classes. They're there for several hours. They drive RAM trucks with Hemis. The engine idles the whole time. The reason is, if they have to take off for an emergency, they don't want to do it with a cold engine or one that won't start.

I don't think I'd ever want to buy one of those trucks!

Walt
 

Mittens

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The Game Warden branch of the Oregon State Police visits some of our Hunter Education classes. They're there for several hours. They drive RAM trucks with Hemis. The engine idles the whole time. The reason is, if they have to take off for an emergency, they don't want to do it with a cold engine or one that won't start.

I don't think I'd ever want to buy one of those trucks!

Walt
Game warden? Emergency?

Hundreds of hours of idle is better than a couple spirited drives on a cold engine?

I don’t buy it.
 

Dannycameo

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So it's just becoming Winter here In the great white North And this is my 1st Winter with my 2022 powerwagon.

About 80% of my mileage is highway miles. getting to trips camping in wilderness etc.

Yet I have high idle hours. Not quite sure how this happened Completely, Yet I recently was I recently was sitting in the truck warming it up as it was 20 below 0. And did a search about the question above on Google.

It seems that the common Agreement is for every idle Hour, = 30 miles Of driving.

I found multiple videos those of Gasser's and diesels with very high idle hours being torn a part for rebuild And it was something else.

Also so for every the idle hour is = 30 miles a driving And every hour is the equivalent of 60 miles of driving.

When I did the math of total hours on my engine times 60 I was low, quite low. because of all the highway driving.

That is a very good thing for this big Gasser, Yes I have high of high idle hours so it's kind of a mixed bag.

I treat the engine as as if it was extreme duty and change the oil every 5000 km With an absolute maximum of 8000 km of highway driving that is. That equals 3000 miles and 5000 miles. I use amzoil only since new on this truck.

And I'm about to send the current oil well into amzoil for oil analysis as a baseline.

I just did it with a car I own And I had results within a week.

Anyway back to the topic, I'm going to be very curious to see what the oil analysis shows with the high idle time, If anything different.⁶⁶99ù9

Here are my numbers on the 6.4 l hemi

292 total engine hours

91 idle

201 Drive

With 15700 km or 10000 miles.

If you do the math for every Engine hours for 60 miles, it is 17500 miles.
It's going to be very interesting this Winter with Remote start when it's 40 below.
Going to try to keep the idle Hours down consciously.
 

crazy jerry

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if you have a factory block heater i would use it
 

Jimmy07

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So it's just becoming Winter here In the great white North And this is my 1st Winter with my 2022 powerwagon.

About 80% of my mileage is highway miles. getting to trips camping in wilderness etc.

Yet I have high idle hours. Not quite sure how this happened Completely, Yet I recently was I recently was sitting in the truck warming it up as it was 20 below 0. And did a search about the question above on Google.

It seems that the common Agreement is for every idle Hour, = 30 miles Of driving.

I found multiple videos those of Gasser's and diesels with very high idle hours being torn a part for rebuild And it was something else.

Also so for every the idle hour is = 30 miles a driving And every hour is the equivalent of 60 miles of driving.

When I did the math of total hours on my engine times 60 I was low, quite low. because of all the highway driving.

That is a very good thing for this big Gasser, Yes I have high of high idle hours so it's kind of a mixed bag.

I treat the engine as as if it was extreme duty and change the oil every 5000 km With an absolute maximum of 8000 km of highway driving that is. That equals 3000 miles and 5000 miles. I use amzoil only since new on this truck.

And I'm about to send the current oil well into amzoil for oil analysis as a baseline.

I just did it with a car I own And I had results within a week.

Anyway back to the topic, I'm going to be very curious to see what the oil analysis shows with the high idle time, If anything different.⁶⁶99ù9

Here are my numbers on the 6.4 l hemi

292 total engine hours

91 idle

201 Drive

With 15700 km or 10000 miles.

If you do the math for every Engine hours for 60 miles, it is 17500 miles.
It's going to be very interesting this Winter with Remote start when it's 40 below.
Going to try to keep the idle Hours down consciously.
Hmmm…interesting math.
Since all my idle hours are done with the transmission in park, they all equal 0 miles of driving.
 

REDNECK28871

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I agree with MIKERU I just want some one to tell me with any technical data how MDS CAUSES any cam, lifter deteriation?! Oil pressue is oil pressure oil delivery is oil delivery. The oil pump delivers pressure PERIOD! weather the cylinder is getting fuel deliverd to it OR NOT and or if spark is available OR NOT. MDS
Has nothing to do shutting down oil pressure to variable cylinders. MDS does not shut down oil delivery to the cylinders that is not running.
 

JerryETX

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werd. one of our company trucks with 6.4 has over 5000hr idle. another one got wrecked and totaled but had several thousand idle also
I agree with MIKERU I just want some one to tell me with any technical data how MDS CAUSES any cam, lifter deteriation?! Oil pressue is oil pressure oil delivery is oil delivery. The oil pump delivers pressure PERIOD! weather the cylinder is getting fuel deliverd to it OR NOT and or if spark is available OR NOT. MDS
Has nothing to do shutting down oil pressure to variable cylinders. MDS does not shut down oil delivery to the cylinders that is not running.
I would like to know why they continue to put MDS on engines when there is no benefit to it only potential risk even when the majority of owners don’t like the feature at least according to the feedback on this site.
 

HEMIMANN

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I would like to know why they continue to put MDS on engines when there is no benefit to it only potential risk even when the majority of owners don’t like the feature at least according to the feedback on this site.

U.S. Govt. EPA-mandated corporate average fleet fuel economy standards. Auto makers are putting on ridiculous systems to shave every tenth of a percentage point off of fuel consumption they can.

Also ultra-thin engine oils, thermostats in transmission oil lines, and other crazy and expensive gizmos for the holy grail of EPA C.A.F.E. requirements.
 

Mittens

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I agree with MIKERU I just want some one to tell me with any technical data how MDS CAUSES any cam, lifter deteriation?! Oil pressue is oil pressure oil delivery is oil delivery. The oil pump delivers pressure PERIOD! weather the cylinder is getting fuel deliverd to it OR NOT and or if spark is available OR NOT. MDS
Has nothing to do shutting down oil pressure to variable cylinders. MDS does not shut down oil delivery to the cylinders that is not running.
I’ve searched and can’t find anything. Maybe stuff around that cylinder gets cold and tolerances get out of wack?
 
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